Fish oil changes the makeup of gut bacteria in ways that may account for its health benefits, new research suggests.
In a study published in the journal
Cell Metabolism, scientists with the University of Gothenburg reported that diets rich in fish oil versus those laden with animal fats produce very different bacteria in the guts of mice.
The findings suggest that gut bacteria share some of the responsibility for the beneficial effects of fish oil — including weight loss and anti-inflammatory properties — and the harmful effects of lard.
The research also demonstrates that gut microbes are an independent factor aggravating inflammation associated with diet-induced obesity and gives hope that a probiotic might help counteract a bad diet.
"We wanted to determine whether gut microbes directly contribute to the metabolic differences associated with diets rich in healthy and unhealthy fats," said Robert Caesar of the University of Gothenburg. Even though the study was done in mice, "our goal is to identify interventions for optimizing metabolic health in humans."
Co-researcher Fredrik Bäckhed said the findings were unexpected.
"We were surprised that the lard and the fish oil diet, despite having the same energy content and the same amount of dietary fiber — which is the primary energy source for the gut bacteria — resulted in fundamentally different gut microbiota communities and that the microbiota per se had such large effects on health," he said.